Reel drive



J. G. ZUBER REEL DRIVE Aug. 5, 1941;

3 Sheets-Sheet 1 Filed July 13, 1939 1941- J. G. ZUBER 2,251,772

REEL DRIVE Filed July 1:5, 1939 5, Sheets-Sheet 2 wa mg Aug. 5, 1941. J.G. ZQUBER 2,251,772

.REEL muvs Filed July 13, 1939. s Sheets-Sheet s Patented Aug. 5, 1941UNETED stars REEL DRIVE Jehn G. Zuber, Chicago, Ill, assignor to TheBell & Howell Company, Chicago, 11., a corporation cf IllinoisApplication July 13,

4 Claims.

My invention relates particularly to the driving mechanism of the filmreels of motion picture machines although not limited to this use alone.

In the conventional motion picture machine the film is positively drivenby the mechanism of the machine and is drawn from a roll thereof on afeed reel and wound on a take up reel which is driven with the mechanismof the machine by means of a suitable yielding driving mechanism, a

the yielding take up reel driving mechanism accommodating for theslowing up of the take up reel as the film roll thereon increases indian eter. The conventional yielding take up reel driving mechanismprovides a substantially constant power of the driven or take up reelmember with the result that the take up tension on the film undesirablydecreases as the diameter of the film roll on the take up reelincreases.

One object of the invention resides in the provision of a reel drivewhich automatically varies the power of a reel member in inversecorrespondence with the speed thereof with a view toward maintaininguniform take up tension irrespective of the diameter of a roll of filmon the take up reel and which automatically varies the driving ratiobetween the mechanism of the machine and the reel to the end that theslowing up of the take up reel as the film roll thereon increases indiameter is accommodated by variance of the aforesaid driving ratiorather than by the usual frictional slip driving device.

Another object resides in the provision with such mechanism of means foreffecting maximum power of the reel member at high speed for the instantpurpose of rewinding the film at high speed.

With these objects in view my invention consists in certain features ofnovelty in the construction, combination and arrangement of parts bywhich the said object and certain other objects, hereinafter appearing,are effected all as fully described with reference to the accompanyingdrawings and more particularly pointed out in the appended claims.

In the said drawings Figure l is a side elevation of a reel driveembodying my invention, with parts removed;

Figure 2 is a sectional View substantially on the line 2-2 of Figure 1;

Figure 3 is a section taken in the axial plane of the rotating elementsof the mechanism;

Figures 4 and 5 are diagrammatic illustrations of the device showingdifferent operating conditions;

1939, Serial No. 284,280

Figure 6 is a partial side elevation of the reel spindle assembly of thedevice with the reel spindle partially broken away and shown in sectionand with parts in partially assembled position thereon; and

Figure 7 is a partial sectional View substantially on the line 'l-'! ofFigure 3.

Referring to the drawings, I designates a frame arm one end of which isarranged, as designated at 2, for attachment to a motion picturemachine. The other end portion of this arm is provided with an enclosingflange 3 extended longitudinally of the arm, and a similarly elongateddetachable flanged cover 4 cooperates with the flange 3 to form anenclosure 5. See Figures 1, 2 and 3.

A film reel spindle 6 extends through a bore 1 through the arm I in theregion of said other end of the arm and is rotatably mounted in thisbore by means of a roller bearing 8. The spindle 6 extends within theenclosure 5 and one end thereof projects from the frame arm and forms areel mount portion 9 upon which a film reel, not shown, may bedetachably mounted in driven engagement with the spindle as is usual.

Two spaced and parallel studs II and I2, both spaced from the reelspindle 6 and parallel thereto, are secured on the arm I, as designatedat 13, these studs and the spindle 6 being disposed in a common axialplane extending longitudinally of the frame arm I and these studsprojecting within the enclosure 5. See Figure 3.

Two pulley members I4 and I5 are rotatably mounted on the stud I Iwithin the enclosure 5 by means of roller bearings I6, and two pulleymembers IT and 18 are rotatably mounted on the stud I2 within theenclosure 5 by means of roller bearings I9. Each of these pulley membersis provided with two belt grooves 2| and thus provides in eiTect twocoaxial angularly fixed pulleys, The pulley members I4 and I5 are sodisposed, with respect to the pulley members I! and I8, that the beltgrooves 21 of the pulley member I! aline respectively with adjacent beltgrooves 2| of the pulley members I4 and I5 and that a belt groove 2| ofthe pulley IB alines with the other belt groove of the pulley member l5.Endless coiled spring belts 22 are trained about the alined belt groovesof the pulley members M, I5, I! and I8.

A stud 23 is secured, as designated at 24, on the frame arm I betweenthe enclosure 5 and the end 2 of the arm and is disposed in parallelismwith the spindle 6 and studs II and I2 and in the common axial planethereof. A pulley member 25 is rotatably mounted on the stud 23 by meansof a roller bearing 26 and is provided with two belt grooves 21 thusproviding in effect two coaxial angularly fixed pulleys. One of the beltgrooves 21 alines with the belt groove 2| of the pulley member I4 whichis not engaged by one of the belts 22, and an endless coiled spring belt28 is trained about these alined belt grooves 2I and 21. An endlesscoiled spring belt 29 is trained about the other belt groove 21 of thepulley member 25 for driving the pulley member 25 from the mechanism ofa motion picture machine, not shown.

The cover 4 is detachably secured on the frame arm I by means of aheaded nut member 3| passing through a bore of the cover andscrewthreaded on the projecting end of the stud I I.

An axially bored pulley 32 within the closure is rotatably mounted onthe spindle 6 in coaxial relation therewith by means of its boreengaging on the spindle and a ball bearing 33, and is provided with abelt groove 34 which alines with the belt groove 2I of the pulley memberI8 which is not engaged by one of the belts 22, and an endless coiledspring belt 35 is trained about these alined belt grooves 2| and 34.

A bored bracket 36 is secured on the frame arm I and a roller bearing 31between the bore of this bracket and the hub of the pulley 32 cooperateswith the bearing 8 to rotatably support the spindle 6 and associatedparts.

An axially bored gear 38 within the enclosure 5 is rotatably mounted onthe spindle 6 by means of a roller bearing 39. The adjacent ends of thehubs of the pulley 32 and gear 38 are provided with opposing clutchformations 4|, and a clutch member 42 extends through a longitudinallyextending diametrical slot 43 through the spindle 6 and is shiftableaxially of the spindle to alternately engage the opposing clutchformations 42 and thus alternately drive the spindle from the pulley 32and the gear 38. See Figures 3, 6 and 7. A ring 44 secured in the boreof the bracket 36 maintains the clutch member 42 radially of the spindle6. A gear 45 on the pulley member I4 meshes with the gear 38 to form apositive drive for the spindle from this pulley member.

The spindle 6 is axially bored as designated at 46, and a rod 41 isslidably engaged in this bore and is provided with a diametrical slot 48in which the clutch member 42 is engaged for shifting the clutch memberwith longitudinal movement of the rod, the projecting end of the rodbeing provided with a knob 49 for the convenient manual shifting thereofto alternate the drive of the spindle as aforesaid.

Assuming the clutch member 42 to be positioned to clutch the pulley 32with the spindle 6, the drive of the spindle from the pulley member 25is effected by a plurality of belt and pulley drives sequentiallyconnected to drive in series and each drive comprises a pair ofrevoluble pulleys and a longitudinally resilient belt trainedthereabout.

Referring to Figures 4 and 5 illustrating the sequentially connectedplural belt and pulley drive of the reel mount spindle 6 under differentconditions of film take up on a motion picture machine, Figure 4illustrates the driving condition where a take up roll of film 5I on areel mounted on and driven by the spindle 6 is relatively small indiameter and Figure 5 illustrates the driving condition where the takeup roll of film is relatively large in diameter as indicated at 52.

Referring to Figure 4 illustrating the driving condition when the takeup film roll 5| is relatively small, the driving stretches 53 of thedriving belts have a tension slightly greater than the non-drivingstretches 54 thereof, this condition being illustrated in Figure 4 byreason of the lines illustrating the driving and non-driving stretches53 and 54 being of the same thickness.

Assuming that the film is fed to the film take up roll at a constantlineal speed, as from the positive film feeding means of a motionpicture machine from which the take up drive is driven, the speed of thetake up film roll and the reel spindle 6 decreases with the result thatthe power thereof is increased and the tension of the driving stretches53 of the driving belts is increased correspondingly as compared withthe tension of the non-driving stretches 54, this condition beingillustrated in Figure 5 by reason of the lines illustrating the drivingstretches 53 being thinner than those illustrating the non-drivingstretches 54. As the power of the spindle 6 increases by the slowing upthereof due to increase in diameter of the take up film roll the drivingstretches 53 of the driving belts feed on to the driving pulleys of thebelt and pulley drives in an increasingly tensioned or stretchedcondition whereas the non-driving stretches 54. of the driving beltsfeed on to the driven pulleys of the belt and pulley drives in a lesstensioned or stretched condition, so that the belts grip the driving anddriven pulleys in correspondingly increasing differences in tension orstretch. As a result the driving ratio between the driving and drivenpulleys changes automatically in correspondence with the slowing up ofthe take up film roll so that the slowing up of the take up film roll asit increases in diameter is accommodated for without consequentfrictional slip, it being observed that the driving ratio accumulatesthrough the sequentially connected belt and pulley drives to the end ofpermitting a relatively large range of take up film roll diameter.

In Figures 4 and 5 the driving pulleys of the belt and pulley drives aredesignated at 55 and the driven pulleys thereof are designated at 56,and in Figure 5 the driving pulleys are shown smaller than they are inFigure 4 to illustrate the driving ratio difierence under the differentconditions of these figures.

The pulley grooves 2|, 2'! and 34 of the drive train pulleys, as shown,are tapered to obtain more belt traction on the pulleys and to augmentthe aforesaid driving ratio difference in that as the driving belts arestretched they decrease in diameter and vice versa, and thus engagedeeper or shallower into the pulley grooves in correspondence with theirinstant tension or stretch.

Assuming the clutch member 42 to be positioned to clutch the gear 38with the spindle 6, the drive of the spindle is effected from the pulleymember I4 through the gear train comprising the meshed gears 38 and 45,this pulley member being adjacent the spindle 6 but drivingly remotetherefrom in the belt and pulley drive. Drive of the spindle throughthese gears effects maximum power of the spindle at high speed for thepurpose of rewinding the film.

While I have thus described my invention, I do not wish to be limited tothe precise details described as changes may be readily made withoutdeparting from the spirit of my invention,

but having thus described my invention I claim as new and desire tosecure by Letters Patent the following:

1. In a reel drive the combination with a revoluble reeling member, of aplurality of belt and pulley drives sequentially connected in series todrive said reeling member, each drive comprising a pair of revolublepulleys provided with tapered belt grooves and an endless coiled springbelt trained thereabout and engaged in said grooves, one of said pulleysbeing coaxial with said reeling member and others of said pulleys beingarranged in two series of coaxial pulleys both spaced from said reelingmember, and a pulley of each pair being angularly fixed with a coaxialpulley of another pair to provide the sequential drive connection ofsaid drives.

2. In a reel drive the combination with a revoluble reeling member, of aplurality of belt and pulley drives sequentially connected in series todrive said reeling member, each drive comprising a pair of revolublepulleys and a longitudinally resilient endless belt trained thereabout,one of said pulleys being coaxial with said reeling member and others ofsaid pulleys being arranged in two series of coaxial pulleys both spacedfrom said reeling member, and a pulley of each pair being angularlyfixed with a coaxial pulley of another pair to provide the sequentialdrive connection of said drives.

3. In a reel drive the combination with a revoluble reeling member, of aplurality of belt and pulley drives sequentially connected in series todrive said reeling member, each drive comprising a pair of revolublepulleys and a longitudinally resilient endless belt trained thereabout,the final drive pulley of said drives being coaxial with said reelingmember and others of said pulleys being arranged in two series ofcoaxial pulleys both spaced from said reeling member, and a pulley ofeach pair being angularly fixed with a coaxial pulley of another pair toprovide the sequential drive connection of said drives, a gear traindrive for said reeling member and driven from one of said pulleysdrivingly remote from said reeling member and including a gear coaxialwith said reeling member, and clutch means operative to alternatelyclutch said final drive pulley and said gear with said reeling member.

4. In a reel drive the combination with a frame arm provided with alongitudinally extending enclosure and a revoluble reeling membercarried thereby, of a plurality of belt and pulley drives disposedwithin said enclosure and sequentially connected in series to drive saidreeling member, each drive comprising a pair of revoluble pulleys and alongitudinally resilient endless belt trained thereabout, the finaldrive pulley of said drives being coaxial with said reeling member andothers of said pulleys being carried with said arm and arranged in twoseries of coaxial pulleys both spaced from said reeling member andspaced longitudinally of said arm, and a pulley of each pair beingangularly fixed with a coaxial pulley of another pair to provide thesequential drive connection of said drives, a gear train drive withinsaid enclosure for said reeling member and driven from one of saidpulleys of the series adjacent to and drivingly remote from said reelingmember and including a gear coaxial with said reeling member, and clutchmeans operative to alternately clutch said final drive pulley and saidgear with said reeling member.

JOHN G. ZUBER.

